1. Field of the Invention
The present invention relates to multipoint strip chart recorders. More specifically, the present invention is directed to a multipoint recorder for recording each of a plurality of input signals in respective ones of a plurality of colors.
2. Description of the Prior Art
Print mechanisms embodying record distinguishing means for multipoint, i.e., multiple input, strip chart recorders have been known and employed for many years. Such print mechanisms generally have operated in a single recording mode and have identified each recorded input quantity under measurement by characteristic mark or color. Multipoint recorders of the multicolor type have previously employed ink wheels which contain ink pads thereof different colors arranged along the periphery of the ink wheel. A selected color is arranged to contact a desired mark on a print wheel before that mark is brought in the printing contact with the record medium, e.g., U.S. Pat. Nos. 3,611,412 and 3,991,676. However, such prior art recorders used a peripherally segmented ink wheel wherein a rotation of the ink wheel was required before the desired color could be aligned with the printing mark. Further, the print indicia on the print wheel was arranged to contact the ink wheel before contact was made between the print wheel and the recording medium. Such a printing mechanism required a complex drive system for achieving the required mechanical interactions. A prior art attempt to simplify the printing mechanism wherein a plurality of print hammers were arranged on one side of the recording medium along with a multicolor ink ribbon or band while the desired print characters were located on the other side of the recording medium on a moving belt is shown in U.S. Pat. No. 3,991,676. However, this prior art recorder also involved a complex and expensive mechanical system including a print head mechanism having hammers arranged across the entire width of the recording medium which produce an uneconomical recording head structure.